1. Field of the Invention
The invention relates generally to insecticides and more particularly to insecticidal formulations for use on domestic animals such as cats and dogs.
2. Description of Background Art
As dog and cat ownership increases, there has been a proliferation of medical and health services available for addressing the needs of sick and aging pets, as well as the maintenance of young and healthy animals. Veterinarians routinely examine pets for diseases and indications of infections including the presence of parasites or various types of cancers. Cats are particularly prone to feline leukemia and may develop diabetes.
Many diseases affecting the health of both cats and dogs are caused by ticks and fleas that act as vectors for viruses and parasites through bites which can transmit blood borne infections. The market for flea and tick products in the US is approximately $552 million and is dominated by about 9 businesses. Although growth between 2007-2012 was 0.6%, the market is expected to increase over the next five years as there is an increasing number of pet owners, particularly those who consider pets as family members and are willing to spend money for the health and well-being of their pets.
There are several disadvantages in current flea/tick products for dogs and cats. Ideally, in order to address one or more of the deficiencies in currently available flea/tick formulations, a product should have: (1) a high concentration of active ingredient(s) to minimize the volume of a topical needed for application to a small dog or cat; (2) liquid formulations that are stable and effective such that flea kill continues for up to at least 30 days from application; (3) a safe product for the consumer in case of skin contact; (4) a formulation that is stable at ambient, low and higher temperatures with a commercially appropriate shelf life; (5) a product that is nontoxic for a dog or cat if ingested; and (6) a product that is ideally equally safe and effective for use on both dogs and cats.
Many available flea/tick topical compositions are not safe and effective for use in both dogs and cats, the two most common household pets. Another drawback of current products is that higher more effective concentrations of the active ingredients are unavailable in stable liquid form.
An effective topical “spot on” application is a commercially desirable feature, particularly if formulations can be applied based on weight and not species basis of the animal. Some liquid spot products for dogs cannot be used on cats.
U.S. Pat. No. 6,867,223 describes insecticide formulations consisting of pryiproxyfen and up to 25% by weight of dinotefuran dissolved in an alcohol, which is described as applicable for use on both dogs and cats. In U.S. Pat. No. 7,368,435, topical endoparasiticidal and ectoparasiticidal formulations combine a macrocyclic lactone and a neo-nicotinoid in addition to permethrin and an insect growth regulator. The first two components are packaged separately to prevent interaction with the permethrin and cannot be supplied as a stable liquid.
Estimated Feline and Canine Populations
Domestic pets in the United States number in the millions with by far the largest contribution from cats and dogs. The United States cat population in 2012 was estimated at over 74 million cats. The US count does not include feral and community cat populations, which are believed to be approximately 50 million. 30-40 percent of households in the US own one or more cats or dogs. The mean veterinary expenditure per household per year for dogs is $378, comparable to that spent on horses, while for cats the cost average is $191. (2012 U.S. Pet Ownership & Demographics Sourcebook).
Table 1 shows the estimated number of cats and dogs in the top ten countries with the highest populations.
Canine and feline populations are highest in the United States; however, cats are more popular than dogs as pets in the United Kingdom and Germany.
Dogs and cats are a major business in the United States. Growth is continuing in development and expansion of dog and cat food with boutique brands and organic feeds enjoying profitable niche markets. New breeds of dogs and cats are appearing, with so-called designer breeds such as labradoodles and cockapoos and the recognition of additional purebred dogs by such organizations as the American Kennel Club.
Consumers are also becoming more familiar with cat breeds, including ancient breeds, domestic and domestic/wild hybrids. There is inconsistency in breed classification among cat registries. At least 55 different breeds are recognized, but a huge number of cats are mixed breeds. Recognized breeds include natural, crossbreeds, and mutations.
The list of recognized cat breeds is long and includes: Abyssinian, Aegean, Australian Mist, American Curl, American Bobtail, American Polydactyl, American shorthair, American Wirehair, Arabian Man, Asian, Asian Semi-longhair, Balinese, Bambino, Bengal, Birman, Bombay, Brazilian Shorthair, British Shorthair, British Longhair, Burmese, Burmilla, California Spangled Cat, Chantilly/Tiffany, Chartreux, Clausie, Cheetoh, Colorpoint Shorthair, Cornish Rex, Cymric, Cyprus cat, Devon Rex Doinskoy, Dragon Li, Dwelf, Egyptian Mau, European Shorthair, Exotic Shorthair, German Rex, Havana Brown, Highlander, Himalayan/Colorpoint Persian, Japanese Bobtail, Javanese, Khao Manee, Korat, Kurilian Bobtail, LaPerm, Maine Coon, Manx, Mekong bobtail, Minskin, Munchkin, Nebelung, Napoleon, Norwegian Forest Cat, Ocicat, Ojos Azules, Oregon Rex, Oriental Bicolor, Oriental Shorthair, Oriental Longhair, Persian, Peterbald, Pixie-bob, Ragamuffin, Ragdoll, Russian Blue, Russian Black, White or Tabby, Savannah, Scottish Fold, Selkirk Rex, Serengeti cat, Serrade petit, Siamese, Siberian Singapura, Snowshoe, Sokoke, Somali, Sphynx, Swedish forest cat, Thai, Tonkinese, Toyger, Turkish Angora, Turkish Van, Ukrainian Levkoy, and York Chocolate Cat.
The list of American Kennel Club recognized breeds includes Affenpinscher, afghan hound, Airedale Terrier, Akita, Alaskan Malamute, American English Coonhound, American Eskimo Dog, American Foxhound, American Staffordshire Terrier, American Water Spaniel, Anatolian Shepherd Dog, Australian Cattle Dog, Australian Shepherd, Australian Terrier, Basenji, Basset Hound, Beagle, Bearded Collie, Beauceron, Bedlington Terrier, Belgian Malinois, Belgian Sheepdog, Belgian Tervuren, Bernese Mountain dog, Bichon Frise, Black and Tan Coonhound, Black Russian Terrier, Bloodhound, Bluetick Coonhound, Border Collie, Border Terrier, Borzoi, Boston Terrier, Bouview des Flandres, Boxer, Boykin Spaniel, Briard, Brittany, Brussels Griffon, Bull Terrier, Bulldog, Bullmastiff, Cairn Terrier, Canaan dog, Cane Corso, Cardigan Welsh Corgi, Cavalier King Charles Spaniel, Cesky Terrier, Chesapeake Bay Retriever, Chihuahua, Chinese Crested, Chinese Shar-Pei, Chow Chow, Cirneco dell'Etna, Clumber Spaniel, Cocker Spaniel, Collie, Curly-Coated Retriever, Dachshund, Dalmatian, Dandie Dinmont Terrier, Doberman Pinscher, Dogue de Bordeaux, English Cocker Spaniel, English Foxhound, English Setter, English Springer Spaniel, English Toy Spaniel, Entlebucher Mountain Dog, Field Spaniel, Finnish Lapphund, Finnish Spitz, Flat-Coated Retriever, French bulldog, German Pinscher, German Shepherd Dog, German Shorthaired Pointer, German Wirehaired Pointer, Giant Schnauzer, Glen of Imaal Terrier, Golden Retriever, Gordon Setter, Great Dane, Great Pyrenees, Greater Swiss Mountain Dog, Greyhound, Harrier, Havanese, Ibizian Hound Icelandic Sheepdog, Irish Red and White Setter, Irish Setter, Irish Terrier, Irish Water Spaniel, Irish Wolfhound, Italian Greyhound, Japanese Chin, Keeshond, Kerry Blue Terrier Komondor, Kuvasz, Labrador Retriever, Lakeland Terrier, Leonberger, Lhasa Apso, Lowchen, Maltese, Manchester Terrier, Mastiff, Miniature Bull Terrier, Miniature Pinscher, Miniature Schnauzer, Neapolitan Mastiff, Newfoundland, Norfolk Terrier, Norwegian Buhund, Norwegian Elkhound, Norwegian Lundehund, Norwich Terrier, Nova Scotia Duk Tolling Retriever, Old English Sheepdog, Otterhound, Papillion, Parson Russell Terrier, Pekingese, Pembroke Welsh Corgi, Petit Basser Griffon Vendeen, Pharaoh Hound, Plott, Pointer, Polish Lowland Sheepdog, Pomeranian, Poodle, Portuguese Water Dog, Pug, Puli, Pyrencan Shepherd, Rat Terrier, Redbone Coonhound, Rhodesian Ridgeback, Rottweiler, Russsell Terrier, Saint Bernard, Saluki, Samoyed, Schipperke, Scottish Deerhound, Scottish Terrier, Sealyham Terrier, Shetland Sheepdog, Shiba Inu, Shih Tzu, Siberian Husky, Silky Terrier, Skye Terrier Smooth Fox Terrier, Soft Coated Wheaten Terrier, Spinone Italiano, Staffordshire Bull Terrier, Standard Schnauzer, Sussex Spaniel, Swedish Vallhund, Tibetan Mastiff, Tibetan Spaniel, Tibetan Terrier, Toy Fox Terrier, Treeing Walker Coonhound, Vizsla, Weimaraner, Welsh Springer Spaniel, Welsh Terrier, West Highland White Terrier, Whippet, Wire Fox Terrier, Wirehaired Pointing Griffon, Xoloitzcuintli, and Yorkshire Terrier.
Flea and Tick Control Products
There are numerous flea and tick control products currently available for use in controlling fleas and ticks on felines. Products from the major manufacturers are sold as monthly topicals, most as “spot on” applications to the skin of the animal. All kill adult fleas and, although most purport to kill ticks; the majority do not kill flea eggs. Products containing fipronil will kill lice but none of those products claim to repel flies.
Most main line manufacturers of flea/tick products employ various concentrations of fipronil, dinotefuran, imidacloprid or etofenprox in combination with pyriproxyfen or (S) methoprene. Few botanicals appear to be effective except for a mixture of natural botanical oils sold by Sergeant's which is stated to be effective against adult fleas, ticks and lice comparable to products containing fipronil. Table 2 lists the active ingredients for some popular commercial products typically supplied as topical treatments.